SKINcredible! Building a form to make a better suture pad
Blog post by SimGHOSTS board member Mark Johanneck.
Are you interested in making your own suture pads for your simulation lab? It has the promise of saving your lab money compared to buying commercially available suture pads. It is certainly easy enough to do if you can follow a recipe and quite frankly it is kind of fun. You get to play mad scientist and mix various materials together and in the end you recreate a pretty reasonable facsimile of human skin.
Smooth-On, Inc. sells the silicone materials you need in order to make your own suture pads. They have provided an easy to follow video you can find online here. There are a few other materials you will need to make the suture pad but those are clearly laid out in the video.
Following those directions exactly was my first introduction into making my own suture pads. It was easy enough but I quickly figured out it was rather time consuming and it didn’t make very many suture pads for the time and effort spent making them. From start to finish the process takes about four hours, although some of that time is spent waiting for the materials to cure before you can continue to the next step. The materials are self-leveling and the video shows using a 12”x12” square with no raised edge. This method means if you use more materials than they suggest it runs off the sides of the square and is wasted. If you follow the directions exactly you spend approximately four hours and end up producing one oddly-shaped suture pad roughly 10”x10” and fairly thin.
If you are now charged with making dozens of suture pads or would like to make them thicker to allow students to practice deep suture technics you can see how this will quickly become very time consuming, resource intensive, and difficult. That was the scenario that challenged me to make a suture pad form which would allow me to mass produce suture pads and make them whatever thickness I desire. With a quick trip to the hardware store and a stop off at the fabric store for vinyl, all costing under $50 in materials, I was ready to build my form.
- 2’ x 2’ sanded plywood (under $10)
- Vinyl fabric - enough to cover the plywood and wrap around the edge
- Look for sale items or remnants.
- The pattern on the vinyl transfers to the skin on the suture pad so look for something that looks like skin surface for the pattern on the vinyl.
- I have found you don’t want to buy vinyl that has any kind of cloth backing. It seems to effect the curing of the silicone.
- 1”x2”x8’ piece of pine board (under $5)
- All-purpose clear silicone caulk that can be used with wood (around $5)
- Small box of wood screws 1” ¼- 1” ½ long (Under $5)
First, you will need to cut the 8’ piece of pine board into four pieces so that you can create a raised edge around the plywood. Each piece of the pine board should be 22” so that it creates a square that matches the piece of plywood. Stretch the vinyl fabric over the 2’x2’ piece of plywood so that the fabric wraps around the edges. I found using a staple gun to attach the fabric to the plywood works much better than using hot glue as suggested in the original video. Once the vinyl is secured with the staples drill pilot holes through the pine board, the vinyl and into the plywood. The next step is to screw in the wood screws to secure the pine board to the plywood. The last step is to use a little bit of the silicone caulk to seal the corners where the pine board comes together as well as the bottom edges of the pine board where it meets the vinyl fabric. Please refer to Figure 1 below.
Figure 1: Construction of skin form
You now have a form that allows you to make a large sheet of suture pad materials which can be made to your desired thickness. Once the material has been poured and cured, you will have a complete product that can be cut to your desired size (Figure 2). The amount of silicone used for each layer will vary depending on the desired thickness of the
suture pad you would like to make.
Figure 2: Completed product
The other change in process from the original video is that you can’t clamp down the Powermesh, which I actually find to work better. I typically cut the PowerMesh to slightly larger than 2’x2’ and make two pieces that size for each sheet of suture pad I create (figure 3). After you have poured the skin layer (epidermis) and just before you are ready to pour the first layer of subcutaneous fat (adipose) carefully place the first layer of Powermesh so that it covers the entire form (Figure 3). Try and make sure the Powermesh fabric is tucked into all the corners so it is directly on top of the skin layer.
Next, pour the subcutaneous fat layer and let it set (figure 3). I add a second layer of Powermesh between the first and second layer of subcutaneous fat for added tensile strength and so there is something for the needle to catch on when doing deeper suture techniques.
Figure 3: Fabric cut larger than frame
I have found that the cost of materials as well as the time and effort to build the form has been resources well spent and will in the long run save our department money in staff time to mass produce the suture pads. Hopefully you have found this post helpful and it inspires you to find new and exciting ways to make improvements to existing process in your own lab.